Luminous Landscape Forum

Raw & Post Processing, Printing => Adobe Camera Raw Q&A => Topic started by: Sylvia Renick on April 30, 2013, 10:21:46 pm

Title: Camera Raw vs DNG import in Lightroom
Post by: Sylvia Renick on April 30, 2013, 10:21:46 pm
I've just purchase Lightroom 4 and have already gotten high-centered on the issue of importing my pictures as raw files or DNG. Is it crazy to save all my raw files to disc as back-up and import as DNG to Lightroom?
Title: Re: Camera Raw vs DNG import in Lightroom
Post by: wolfnowl on April 30, 2013, 10:44:47 pm
If you want you can embed the original raw files within the DNG files.  Depends on how much money you have for storage drives.   :)

Mike.
Title: Re: Camera Raw vs DNG import in Lightroom
Post by: Schewe on April 30, 2013, 11:00:03 pm
Is it crazy to save all my raw files to disc as back-up and import as DNG to Lightroom?

No, it's not crazy, what what exactly are you hoping to accomplish with this? For long term storage, DNG makes a lot of sense. But short term it may complicate things a bit in workflow and backup. Again it depends on your needs...

One thing you should not about DNG is that all of the xmp metadata is stored in the DNG and not in .xmp sidecar files. This can be good or bad depending...yes, it locks all the metadata inside of the DNG and not in a loose sidecar file. But if you are backing up you images using a backup software based on file modification dates, a modified DNG will pop a new modification date and require the backup of the entire DNG file–which can be quite large compared to backing up a tiny .xmp text file. So, if you are using Lightroom and saving all the metadata into the DNG file, those changes force the whole file to be backed up.

I import the original native raw files in Lightroom to work on them and save out the .xmp metadata. At the point where I think I'm "done" with an image and want to embed all the metadata inside of a DNG, I'll convert to DNG from inside of Lightroom...this is done on a project by project basis...

So, you really need to think about your workflow and decide what it is you are expecting to accomplish.
Title: Re: Camera Raw vs DNG import in Lightroom
Post by: kencameron on April 30, 2013, 11:05:14 pm
I went with a full DNG import workflow for a while, but later regretted it when I started using other software that doesn't read DNGs.
Title: Re: Camera Raw vs DNG import in Lightroom
Post by: Sylvia Renick on May 01, 2013, 04:42:52 pm
Thank-you All!
I'm becoming more and more aware of how much I don't know but having access to a forum like this will make learning so much more fun.
Title: Re: Camera Raw vs DNG import in Lightroom
Post by: Bob McAnally on May 09, 2013, 01:34:12 pm
One thing you should not about DNG is that all of the xmp metadata is stored in the DNG and not in .xmp sidecar files. This can be good or bad depending...yes, it locks all the metadata inside of the DNG and not in a loose sidecar file. But if you are backing up you images using a backup software based on file modification dates, a modified DNG will pop a new modification date and require the backup of the entire DNG file–which can be quite large compared to backing up a tiny .xmp text file. So, if you are using Lightroom and saving all the metadata into the DNG file, those changes force the whole file to be backed up.

Jeff, please correct me if I am wrong on this.  A second venerability in use of DNG, while It may not be likely, is that rewriting the DNG to add metadata means that the file that contains the image is rewritten every time metadata is updated, opening that image to corruption if there is an electrical glitch during the write. LR for a RAW file is read only, writing metadata to the xmp file.

Assuming a good backup strategy, this may not be a significant issue, but it is there.

Title: Re: Camera Raw vs DNG import in Lightroom
Post by: digitaldog on May 09, 2013, 03:11:15 pm
A second venerability in use of DNG, while It may not be likely, is that rewriting the DNG to add metadata means that the file that contains the image is rewritten every time metadata is updated, opening that image to corruption if there is an electrical glitch during the write. LR for a RAW file is read only, writing metadata to the xmp file.
Assuming a good backup strategy, this may not be a significant issue, but it is there.

Correct. And if like me, you do this backup stuff unattended and automatically, there's little pain in the strategy.
Title: Re: Camera Raw vs DNG import in Lightroom
Post by: nemophoto on May 30, 2013, 12:54:24 pm
I import the original native raw files in Lightroom to work on them and save out the .xmp metadata. At the point where I think I'm "done" with an image and want to embed all the metadata inside of a DNG, I'll convert to DNG from inside of Lightroom...this is done on a project by project basis...

Great idea. Wish I'd thought of that.  ;D But, Jeff, a big question: Are you doing very little in Photoshop afterward? I find no matter how hard I try, I still do a lot in Photoshop in post, and then have a very different TIFF from my RAW. (My RAW is simply my starting point.) Any thoughts on what some have suggested -- saving the TIFFs as DNGs? Personally, I can't see the reasoning, but maybe there's a good one.

Nemo
Title: Re: Camera Raw vs DNG import in Lightroom
Post by: Schewe on May 30, 2013, 01:03:32 pm
I do send heros to Photoshop yes...and save them as layered 16 bit ProPhoto RGB TIFFs which come back to Lightroom where I may edit on top for soft proofing and such before printing...but saving TIFFs as DNGs is a solution looking for a problem. It doesn't get you anything other than a TIFF stuffed into a DNG.
Title: Re: Camera Raw vs DNG import in Lightroom
Post by: nemophoto on May 30, 2013, 01:07:26 pm
Thanks. My thoughts exactly (TIFFs to DNG), but nice for an additional confirmation.
Title: Re: Camera Raw vs DNG import in Lightroom
Post by: Martin Potter on January 12, 2014, 12:55:02 pm
I've been toying with this myself (using DNG for LR and having the NEFs backed up on import) and came across this post whilst googling for some advice.  Anyway, it seems that in LR5 at least the DNG files are left untouched by any edits made (including metadata) - this blog post (http://blogs.adobe.com/jkost/2013/08/dng-verification-in-lightroom-5.html) from Adobe seems to confirm it, as did my own (admittedly limited) tests.

regards,
Martin
Title: Re: Camera Raw vs DNG import in Lightroom
Post by: Tim Lookingbill on January 18, 2014, 02:07:38 pm
I've been toying with this myself (using DNG for LR and having the NEFs backed up on import) and came across this post whilst googling for some advice.  Anyway, it seems that in LR5 at least the DNG files are left untouched by any edits made (including metadata) - this blog post (http://blogs.adobe.com/jkost/2013/08/dng-verification-in-lightroom-5.html) from Adobe seems to confirm it, as did my own (admittedly limited) tests.

regards,
Martin

Thanks for that Adobe blog link, Martin. The subsequent nested links lead me down a digital worry wort's worst rabbit hole with a new term referred to and mentioned in the Peter Krogh DAM article linked in your Adobe DNG Validation blog called "Bit Rot"...

http://en.wikipedia.org/wiki/Bit_rot

Here's the Peter Krogh DAM article...

http://thedambook.com/dng-verification-in-lightroom-5/